An aerosol is a suspension of small solid or liquid particles in a gas. Such suspensions may occur naturally or may be man made. The particles in the aerosol may be bacteria, fungi, viruses, toxins, various solid or liquid chemicals and so on. There is a need for the qualitative and quantitative analysis of this type of suspension. In order to analyse an aerosol, at least the component of interest must be collected. This may be done by dissolving or suspending the component in a liquid. According to current practice, this is done with "bubblers" and "impingers".
In a bubbler, the aerosol is broken up into a dispersion of small bubbles passing through a body of liquid. With such a device, the collection efficiency for particles of greater than 1 micrometer in size can be low and non reproducible.
In an impinger, a high speed jet of aerosol is directed against the liquid surface. These devices require high flow rates, thus limiting their utility. It has also been observed that the efficiency of an impinger when dealing with particles composed of two or more organisms is not good.